This invention relates to a system for selecting processors and, in particular, to a processor-selection system for determining job allocation to a plurality of processors, so that they can be operated efficiently.
It is conventional practice to build a computer system by using a plurality of processors. Using this system, various operation processes are performed, on a distribution basis, by the plurality of processors, the inputting and outputting of data also being controlled in the aforementioned way.
In the conventional ordinary multiprocessor system, various tasks are divided into a plurality of processing units and, for each processing unit, a suitable processor is allocated for the task to be executed. It is, therefore, necessary to prepare a plurality of processors for various tasks.
Signal transfer is initially determined relative to a corresponding processor or processors, and it is necessary to execute a predetermined information-processing task in accordance with a program sequence. There is a tendency for the respective processors to have an increasing number of processing functions. Therefore, it is proposed that a plurality of processors incorporated into a multiprocessor system be able to execute the same task. For example, it is current practice to incorporate into a multiprocessor system, processors capable of high-speed operation and equipped with a high-performance printer, and processors having a low-speed of operation and equipped with a low-performance printer. In this case, it is preferable to execute an operation using the high-speed processor, and to print the result of the operation using the high-performance printer. Where, on the other hand, the processor provided with the high-performance printer is occupied with operation processing, it is then preferable to transfer processing information to the processor equipped with the low-performance printer and to print it thereon.
Since the sequence of information-transfer among the processors is predetermined in the conventional system, an additional processor, if present, cannot be utilized for processing, for example, the same task. Furthermore, if the number of processors participating in the system changes, such as a processor being eliminated from or added to the system, then the system cannot execute a job in accordance with a proper processing procedure unless it has been reprogrammed beforehand.